Electric switch



(No Model.)

C. E. DAVIS.

ELBGTRIG SWITGH. No. 476,613. Patented June '7, 1892'.

SCS

UNITED STATES PATENT OFFICE.

CHARLES E. DAVIS, OF CHICAGO, ILLINOIS.

ELECTRIC SWITCH.

SPECIFICATION forming part of Letters Patent No. 476,613, dated .T une7, 1892.

. Application filed February 20, 1891. Serial No. 382,136. (No model.)

To all whom t may concern:

Be it known that I, CHnELEs E. DAVIS, of Chicago, Illinois, haveinvented certain new and useful Improvements in Electric Switches, ofwhich the following is a specification, reference being had to theaccompanying drawings,in which similar letters of reference indicatelike parts in all the iigures.

My invention relates to that class of electric switches in which arevoluble bar by its successive partial rotations alternately makes andbreaks contact with the electric terminals mounted on the base, therotation of the bar being checked during the charging of an elasticconnection between the bar and an arbor mounted in the base and adaptedto manual rotation and then suddenly released, causing both the makingand breaking of the contact with the terminals to be quick, sharp, andsudden; and my invention consists in this regard in adapting therevoluble contact-bar to be moved laterally out of engagement with afixed catch upon the base and to be rotated partially and retracted toengagement with a succeeding catch. v

My invent-ion also relates to improved means for preventing reverserotation of the bar and the arbor, to improvements in thebinding-terminals on the base for admitting ready attachment of thecircuit-wires, and to improved means for insulating the metallic partson the under side of the base from possible contact with the wall orstructure to which my improved switch may be attached; and myimprovements consist in the devices shown in the drawings and explainedand claimed hereinafter. v

In the drawings, Figure l shows a plan view of my improved switch. Fig.2 shows a section of the same through the line y y'. Fig. 3 shows theposition of the parts after the bar has been moved laterally out ofengagement with the catch and is about to rotate under the influence ofthe charged elastic connection between the bar and the arbor. Fig. it

is a section of Fig. l through the line .oc a, showing the constructionof the binding-terminal. Fig. 5 is an end view of the revolublecontact-bar. Fig. G is an under view of the base, showing the method ofinsulation. Fig. 7 is a view showing the catches for checking rotationand the secondary catches for preventing reverse rotation. Fig. 8 is asection of Fig. 6. Fig. 9 shows an alternate form of the checking andsecondary catches.

In the figures, B is the base, composed of wood, porcelain, or othersuitable insulating material and provided with binding-terminals T forthe reception of the line-wires and with terminals t, preferablyelastic.

C is the revoluble contact-bar, adapted to form contact with thebrush-terminals t and to break contact therewith when partially rotatedto the position shown bythe dotted lines in Fig. 3.

D is an arbor mounted in the base through the bushing cl, expanding onthe upper side of the base, as shown in the figures. The expanded partis provided upon its periphery with four indentations d', whose purposewill appear. l

The bar C is provided with a slot, through which passes the arbor D, andwhichadapts the bar to a lateral as well as a rotary movement on thearbor.

The bar C is provided with a downwardlyextending projection c, which isadapted to enter the indentation or catch d and check the rotation ofthe bar until released by a lateral movement thereof, as shown in Fig.3, which lateral movement is permitted by the slot.

Around the arbor D and having one end secured thereto is the spiralspring s, having its free end projecting radially and in contact with alug c on the bar andadapted by such contact when charged by rotation ofthe arbor to rotate the bar C. There is also projecting 'from the arborD the pin 7i, normally pressing against the back-stop c", preventingrotation of the arbor D in the reverse direction and maintaining alwaysa certain amount of tension on the spring s, whereby the bar is heldnormally in a retracted position, with the projection c in engagementwith the catch CZ. The bar C is also provided with the lug c, with whichthe pin 7i is adapted to engage when the arbor is forwardly rotated andwhich is at some little distance from the back-stop 0', so that there isa certain amount of lost motion on the part of the pin 7L between them.

In the operation of my device the first motion of the arbor causes thepin 7L to leave the IOC to the position shown by the dotted lines inFig. 3, causing an instantaneous separation of the ends of the bar fromthe terminal brushes t and making a double'break in the circuit.

It will be observed that the radius to the point of contact between thespring s and the projection c on the bar lies at about a right anglewith the line of lateral movement of the bar, so that the spring sopposes the action of the pin 7L in moving the bar laterally out ofengagement with the catch. This disposition of parts causes the spring sto retract the bar laterally, bringing the projection c to its normalradial distance from the arbor D and adapting it to be engaged by thesucceeding catch d. This retraction is permitted from the fact that thepin 7L moves only with the arbor, and instantly upon the rotation of thebar the lug c advances out of the control of the pin, which is permittedby the lostmotion between the lug c and the back-stop 0. Theindentations d have both a forward and a rear face, as shown in Fig. 7,the forward faces acting as a series of catches to check the rotation ofthe .bar and the rear faces acting as aseries of secondary catches toprevent reverse `rotation thereof. This prevention of reverse rotationis necessary both for the reason that there would not be a suihcientlyquick make and break of contact in operating the switch in that manner,but also it prevents rotation of the arbor D and enables me to unscrewthe thumb-screw M on the arbor D and remove from the switch the shell N.

In Fig. -t is shown a section of myimproved terminal, which consists oftwo parts, one part T provided with the binding-screw for attaching thewire and the other part t consisting of a brush and adapted to establishan elastically-supported contact with the bar C. The part T, bearing thebinding-screw P, is bent at an angle, as shown in Fig. 4, adapting it tobe attached to the surface of the base, with the part carrying thebinding-screw deflecting into the aperture 7c neither horizontally norvertically, but at about the angle shown in Fig. Lt. This disposition isof especial advantage in bringing the binding-screw beneath the surfaceof the base and out of the way of the rotating bar C, in admitting theready placing of the wires between the head of the binding-screw and theterminal without the necessity of more than a trifling bending of thewire, and at the same time renders the binding-screw accessible for useof a screwdriver in manipulating the binding-screw. The side walls ofthe aperture K serve to retain the alignment of the terminal whenattached to the base by a single screw u. The part t is made thinnerthan the part T to give it elasticity, as above explained. The free endis bent suitably to form contact with the bar, and the other end isbifurcated, as shown in Figs. 1 and el, and is placed upon the basebeneath the part T and secured thereto by the same screw u, thebifurcations extending on each side of the part T, andthus with asinglescrew I attach the two parts to the base and maintain them in properposition.

To prevent possible -contact with the wall to which my switch may beplaced of the metallic connections on the under side, I forni the basewith a sort of wall around each of the metallic parts, as shown in Fig.G, and into the interior I put any well-known vitreous insulatingmedium. I am aware that the metallic parts have been insulated bycovering them with plastic or vitreous insulation placed in countersunkholes in the base, and I do not claim that, my purpose being to effect asaving in material and to decrease the weight of the base, andtherefore, insteadof making the general section of the base so thick asto admit of countersinking the holes, I place the metallic parts on thegeneral level of -the thin base and surround them with a wall of thesame material.

In the drawings I have shown the catches as being formed in theperiphery of the eX- panded stationary bushing around the arbor. I donot wish to limit myself to this construction, all that is requiredbeing a face presented to check the forward rotation of the bar, asecondary face adapted to prevent reverse rotation thereof, and meansfor guiding the engaging projection on the bar over the face of thesecondary catch, so that it maybe retracted by the spring s intoengagement therewith. I may do this by placing four separate studs inthe base, as shcwn in Fig. 9.

What I claim as new, and desire to secure by Letters Patent, is A l. Inan electric switch, the combination of a base B, a switch-bar C, havinga straight slot therein, the catches d, the co-operating pin c, thearbor D, provided with the pins h, adapted to engage with the switch-barand to move it parallel to itself out of engagement with the catch d',with which it is in contact, and the spring s for rotating the bar andretracting it to engagement with the succeeding catch.

2. In an electric switch, the base having the catches d', the(3o-operating pin c thereon, the slotted switch-bar, a projecting pin,as 7L, on the arbor, engaging in both directions with projections on theswitch-bar, with lost n10- tion between them, and the spring s on thearbor, in engagement with the switch-arm, combined and operatingsubstantially as described.

3. In an electric switch, the combination of the base D, the catches, asCZ', the (3o-operating pins c, the slotted switch-bar C, the arbor D,

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'a lost-motion-engaging connection between brush t, having one endbeneath the thick the arbor D and the bar C, adapted to move part T,which is secured to the base and which the bar laterally ont ofengagement with the clamps the brush thereto by means of the catch d andpermit its rotation and retraction screw u.

5 to a succeeding catch. Executed this 11th day of February, 1891. 15

4. In an electric switch, the base provided with an aperture for thepassagero the line- CHARLES E. DAVIS. Wire, a binding-terminalconsisting of the In presence Of thick part T, bent angularly into theaper- A. M. HEYL,

1o ture and provided with a screw P, and the E. JOHNSON.

